1. Field of the Invention
The invention relates to a sluice arrangement for the sluicing out of clinker and uncombusted residue from combustion furnaces, i.e. the residual material which is discharged from the discharge end of a fuel-transporting grate, or from a rotary kiln.
The arrangement is well suited for furnaces fired with poor solid fuels, especially incinerator furnaces for household refuse, but may be used for any furnace where clinker and slags are discharged.
2. Description of the Prior Art
In one-furnace plants, the material in question usually is discharged either directly to a clinker or ash pit, or to conveyor means, transporting the material to the clinker or ash pit.
In multi-furnace plants, there may be separate clinker or ash pits for each furnace, or the material may fall onto conveyor means which discharge the material into a common clinker or ash pit.
The arrangement according to the invention is usable in one-furnace as well as multi-furnace plants at the place where the hot residual material discharged from one or more furnaces is transferred to the store which it is sooner or later removed from the plant.
From the prior art it is known to sluice out the residual matter, such as slags and clinker, through a siphon trap. The discharged material flows through a shaft, the end of which dips down under the water surface in a water-filled basin; the material is cooled through contact with the water and then settles on the bottom of the basin from where it is removed by suitable conveyor means such as a scraper conveyor.
This system has the advantage of ensuring an effective cooling of the discharge uncombusted material and providing for an effective seal, preventing false draught to the flue gas ducts. However, the erection as well as the operation costs are rather high. Also, it is rather water-consuming and difficult to repair during operation. Moreover, fine particles contained in the discharged material or split off from layer clinker dropping into the water may collect as a slurry-like mass on the surface of the water, from where it must be removed, and the conveyor means are subject to heavy wear.
It is also known to perform the sluicing-out without the use of a water trap, for instance by means of a screw conveyor mounted in a tube-formed guide, or by a system of push-pistons, pushed along a duct which has its base in the side wall of the ash pit, near the bottom, and whose cross section is the same as that of the pistons. These conveyor means can, however, hardly stand temperatures as high as 900.degree.-1000.degree.C which may well be reached, and by this known dry-sluicing it is furthermore difficult, or impossible, to attain a sufficient degree of tightness, which may unintentionally cause false draught through the ash pit to the flue ducts.
In instances in which the material which has fallen down in the pit contains voluminous elements such as scrap, which is common occurrence in incinerator plants for household refuse and the like, none of the above sluicing-out systems are suited, as such parts either cannot be sluiced away in the manner described, or will entail great risks of the system being jammed or damaged.
It is a purpose of the invention to procure a sluicing-out arrangement of the kind described in the preamble, and moreover an arrangement which does not have the defects outlined above, which can be installed at relatively low costs, and which permits a safe and particularly advantageous operation.
Furthermore, the invention includes a method for the operation of the above-mentioned arrangement and a pilot system for automatic control of the arrangement during this operation.